Alcohol: Men who have two to four drinks a week had a 26% lower risk of diabetes, compared with abstainers. Those who have one or more drinks a day had a 43% lower risk.

Nuts: Women who ate nuts or peanut butter five times a week had a 20% to 30% lower risk than women who only rarely eat nuts or peanut butter.

Fiber: People who eat a diet rich in whole grains have a 40% lower risk of diabetes compared with those who eat a low-grain diet.

Because many patients who reverse their diabetes through lifestyle changes go unreported, USC has established the Diabetes Mellitus Reversal Registry at www.dmrr.org. Modeled after the National Weight Loss Registry, the registry aims to document and validate methods patients have used to reverse their diabetes and share what methods have worked. Anyone who has reversed his or her diabetes is encouraged to log in.